m29dw256g Numonyx, m29dw256g Datasheet - Page 26

• Manufacturer Part Number: m29dw256g
• Description: 256-mbit X16, Multiple Bank, Page, Dual Boot 3 V Supply Flash Memory
• Manufacturer: Numonyx

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6.1
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6.1.3
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Command interface
All bus write operations to the memory are interpreted by the command interface.
Commands consist of one or more sequential bus write operations. Failure to observe a
valid sequence of bus write operations will result in the memory returning to read mode. The
long command sequences are imposed to maximize data security.
Standard commands
See either
Read/Reset command
The device is in read mode after reset or after power-up.
The Read/Reset command returns the memory to read mode. It also resets the errors in the
status register. Either one or three bus write operations can be used to issue the
Read/Reset command.
The Read/Reset command can be issued, between bus write cycles before the start of a
program or erase operation, to return the device to read mode. If the Read/Reset command
is issued during the timeout of a block erase operation, the memory will take up to 10 μs to
abort. During the abort period no valid data can be read from the memory.
The Read/Reset command will not abort an erase operation when issued while in erase
suspend.
Auto Select command
The Auto Select command puts the device in auto select mode, when using the in-system
method (see
read the manufacturer code, the device code, the protection status of each block (block
protection status) and the extended memory block protection indicator.
Three consecutive bus write operations are required to issue the Auto Select command.
Once the Auto Select command is issued, bus read operations output the following to
specific addresses:
The memory remains in auto select mode until a Read/Reset or CFI Query command is
issued. (See
Read CFI Query command
The memory contains an information area, named CFI data structure, which contains a
description of various electrical and timing parameters, density information and functions
supported by the memory. See
Table 39
(CFI) memory area.
the manufacturer code
the device code
the extended memory block protection indicator
a block protection status.
and
Table 10
Section 3.7: Auto select
Table 10.: Standard commands
Table 40
for a summary of the standard commands.
for details on the information contained in the common flash interface
Appendix
mode). When in auto select mode, the system can
B,
Table
in conjunction with
35,
Table
36,
Table 37, Table 38,
Table 7.: Block
protection.)